This invention relates to a wiper system for windshields of motor vehicles, and more particularly to a wiper arm which can be attached to an oscillatorily drivable wiper shaft and have a washing fluid line extend within the wiper arm.
It is common practice today to provide washing nozzles directly at the wiper arm or at the wiper blade in which the washing fluid is supplied through a fluid line extending along the wiper arm. The attachment piece of the wiper arm is known to be covered by a cap made from plastic material. This cap protects the connection between the wiper arm and the wiper shaft. This cap also improves the appearance if the wiper arm is connected to the wiper shaft outside of the vehicle body. On the other hand, many modern motor vehicles are provided with a slot between the windshield and the motor hood, out of which the wiper arms project. The wiper shaft is located below the slot opening so that it is covered by the body sheet. Consequently, a cover is no longer provided. As well as in the case of wiper arms with a cover as in the case of wiper arms without a cover, it may be necessary to safely retain the fluid line in the area of the attachment piece.
A fluid line extending through a sleeve-shaped holding element adjacent a wiper arm comprised of a covered attachment piece is known from German Patent DE-GM 87 06 029.
Also, wiper arms are already known wherein a washing fluid line extends within a U-shaped joint piece. This, for example, is shown in German Patent DE-OS 25 09 876. In particular the fluid line protrudes through the attachment piece and extends throughout the joint piece after passing beneath the hinge of the joint piece. Washing fluid line passages through the wiper shaft are known from U.S. Pat. No. 3,887,956 and from German Patent Nos. DE-OS 39 07 967 and DE-OS 39 07 968. This arrangement also requires the fluid line to extend beneath the hinge of the joint piece.